This invention relates generally to automatic ice makers, and more particularly to detecting ice readiness in a belt ice maker which contains water during formation of ice cubes and from which the formed ice cubes are later released.
Refrigerator ice makers typically form ice cubes in the freezer compartment and release the formed ice cubes through a dispenser located in a freezer compartment door. Refrigerator ice makers of the elastomer belt type include an elastomer belt, or mold, having a plurality of cube compartments. Water freezes in the cube compartments to form ice cubes, and the fully frozen cubes are discharged, or released, from the cube compartments into a container. Belt ice makers do not require as much space as, and have a higher ice rate, (i.e., make more ice) than, many other types of ice makers.
Although belt ice makers provide the advantages mentioned above, determining whether ice is completely frozen in a belt ice maker is difficult. Specifically, a temperature measurement typically is utilized to determine whether water in a cube compartment is completely frozen and ready to be dispensed. In a belt ice maker, however, the mold moves and has a low thermal conductivity. Therefore, a thermistor, thermocouple, or other temperature sensor has to be in sliding contact with the mold, and accuracy of a temperature sensed is impacted by freezer air temperature and air velocity.
Releasing less than completely frozen ice cubes into a container in a freezer is not desirable since the unfrozen water then freezes in the container and multiple cubes may be frozen together. Also, unnecessarily maintaining fully frozen ice cubes in a mold adversely impacts the ice rate of the ice maker.